Ivan Detkov: After S1Q1 any next move is unnecessary. The group is alive "as is". It is probably too complicated to explain it here for beginners. R1 settles the issue. T3 is weak as TwT correctly explained.
caranthir: Was the problem different at the time it was discussed? In this version, after B1D1 the four stones are in atari and the next move is mandatory.
Meghan Furrie: (Thread one) After B19D19 - A17 should not be a loss, it is still alive and can kill to live.
TwT: Dear Meghan,
Thank you for your first comment. After A3, the group is indeed alive, but it is inferior to playing C1 to capture two stones for three reasons:
(1) A4 becomes a big sente endgame move. (2)
D1 could be captured.
(3) It leaves no KO threats.
Meghan Furrie:
Was the problem different at the time it was discussed? In this version, after B1 D1 the four stones are in atari and the next move is mandatory.